Method for production of cyanogen compounds.



A. R. LINDBLAD.

METHOD FOR PRODUCTION OF CYANOGEN COMPOUNDS. APPLICATION FILED nov- 11. 1914.

1 1 87,633 Patented June 20, 1916.

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METHQD F01?) PRODUGTIOhT 0F CYANOGEN CQMEQUNDS.

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application. filed November The present invention has for an object synthetic production of cyanogen .compounds or other compounds formed of cyanogen compounds.

Several experiments have been made to produce cyanogen compounds out of carbon and nitrogen through direct synthetis usually in the presence of an alkali compound, or .alkaline earth compounds to obtain cyanids or cyanates of metals. This synthesis has appeared possible but for industrial work none of the methods hitherto propOS'; l could be used. The principal reasons are partl t it is difficult to supply the heat necessary for carrying out the reaction which is in a high degree endothermic and partly that the brickwork of the apparatuses used very soon'gets spoiled by 'the influence of the melted alkaline compounds. For this reason the mind was directed on the use of electric furnaces and experiments in that respect have also earlier been made. The results became howeverequally bad as by the heating in retorts before undertaken, the electric current followed the inner walls of the furnace chamber which had for effect that said walls were burnt down and besides this destroying influence of the alkalis on the furnace material was equally bad as before. According to investigations'made by me one of the chief reasons of this negative result consists in the form of the electric furnace which was not suitable for this purpose. Said furnace namely consisted in a cylindrical shaft with carbon electrodes entering through the walls of the same. At

the heating of the charge the alkalis contained in the charge melted and flowed down along the walls of the shaft. Melted salts being comparatively good conductors for the electric current, the'result was, that only one part of the'current flowed the proper way through the charge, while another part flowed along the walls, thereby heating and destroying them.- In order to obviate these difficulties according to the present invention an electric furnace is used which is so Specification of Letters Patent.

Patented June 2d, 1916.

17, 191%. Serial No. 8725353.

constructed that the horizontal sectional area of the furnace chamber at one or several places is greater than. at above. lying parts of-the furnace chamber for which purpose, at that place or places, the furnace chamber .is given the form of a cone or a pyramid or another form which fulfils said conditions. Thereby the melted alkalis are hindered to flow down along the walls of the furnace forming a path for the electric. current, but the current is forced to flow the way aimed at, whereby the furnace material is preserved against the destroying action of the current.

. In order to make the invention more clear there is shown on the accompanying drawing two suitable forms of a furnace for carrying out the present method.

Figure 1 shows one form of the furnace in vertical section and Fig. :2 shows in the same way a somewhat modified form of the furnace chamber.

in the did-erect figures corresponding parts are indicatedwith the same designation.

The invention is first described with regard to Fig. l. 1 is the furnace shaft, which at its bottom opens into a wider furnace chamber 2. 3 are the electrodes, through which the electric current is supplied to the charge, 4. are contact members for leading the current to the electrodes, 5 are watercooled frames intended to strengthen the brickwork at those places, where the electrodes are introduced. 6 are conduits for supply of gaseous nitrogen. 7 is a discharge conduit for gas formed during the process. 8 is a taphole for slag and other materials, being removed from the furnace in liquid form.

' As above stated the same designations in Fig. 2 indicate corresponding parts as in Fig. 1.

According to the form shown in Fig. 2 the furnace chamber is given such a' form, that one or several free gas spaces will arise between the brickwork of the furnace and hit compound for instance potassium carbonate K CQ, or potassium hydrate KOI-l. The carbon is suitably supplied in the form of charcoal, the gaseous nitrogen ought to be comparatively pure and can be manufactured in any of the usual manners, for 1nstance through fractionated distillation of air. The carbon and potassium compound are introduced through the charging device arranged in the upper part of the shaft. Necessary electric energy is supplied through the electrodes 3, and nitrogen is blown in through the conduits 6. If the temperature is kept sullicientlyhigh by the of the electric current, the reaction is going on, 1f

potassium carbonate is used as raw material,

substantially according to the formula:

K CO +4C+2N==2KCN+3CO or if potassium hydrate is used Of course the reaction is not going on dioxid and other compounds. The formulas above given may therefore only be considered as to state the principal reactions. Generally it is suitable to use so high a temperature, that the cyanogen compounds obtained escape in gaseous state. This is of course not necessary, but involves several advantages, as for instance less impurities in roducts obtained, simplified work and the so orth. For evaporating the cyanogen compounds it is however not necessary to keep a temperature corresponding to their boiling points. Already at a considerably lower temperature its vapor pressure is so high, that the evaporation is possible. Then they go off in the form of smoke together with the escaping gases. The cyanogen compounds leaving the furnace are condensed and collected in suitable receivers, not shown and not being an object for the present invention.

Under certain conditions it may be suitable to blow in the gaseous nitrogen only or substantially from the one side. Ifthe outlet for the gases formed is arranged as shown on the drawin the nitrogen ought to be blown in from t e side, located 0 po-' site to this outlet, in order thereby to force the nitrogen during a long time to be in con tact with the other materials charged into the furnace. Further it may also be advantageous to charge the potassium compound at the one side of the furnace. In Fig. 2 is shown a charging device intended for such a charging.

Analogous to the manufacturing of potassium cyanid also several other cyanids are manufactured, especially the sodium cyanid,

instance for synthetic manufacture of ammonia. In this case the cyanogen compounds obtained in the above stated manner are decomposed by means of overheated water-steam or in other ways, Whereafter the alkali compounds thereby generated are re-introduced into the process. In the case water-steam is used, this part of the process passes on for instance according to the following formulas:

KCN+2H,O:NH,+KOH+CO KCN+2H,O:NH,+HCOOK.

If cyanate has been formed as primary roduct, the reaction is thought to take the ollowing course;

Having thus described my invention, I declare, that what I claim is:

1. A process for the production of cyanogen compounds of the class herein described consisting in charging the material used into a; melting chamber of an electric furnace in a downward direction, causing the charge to spread and form outwardly sloping surfaces, supplying electric current to the charge at said sloping surfaces, and in troducin gaseous nitrogen into the chamber so t at it comes in contact 'With the charge when heated by the electric current.

2. A process for the production of cyanogen compounds of the class herein ,described the points of supply of the electric current.

3. A process for the production of cyanogen compounds of the class herein described consisting in charging the material used into a melting chamber of an electric fur nace in a downward direction to allow the charge to spread and form outwardly sloping surfaces, supplying electric current to the charge at said sloping surfaces, introducing gaseous nitrogen into the melting chamber so that it comes in contact with the charge when heated by the electric current,

the said nitrogen being introduced at one side of the charge, and conducting the cyanogen compounds formed out of the said chamber from the side thereof opposite to the point of introduction of the nitrogen.

at. A process for the production of cyanogen compounds of the class herein described consisting in charging a mixture of carbon and metal compounds into a melting chamber of an electric furnace in a downward direction, causing the charge to spread and form outwardly sloping surfaces, supplying electric current to the charge at said sloping surfaces, introducing gaseous nitrogen into the melting chamber, and leading off the cyanogen compounds formed and collecting the same.

A process for the production of cyanogen compounds of the classherein described consisting in charging a mixture of carbon and metal compounds into a melting chamber of an electric furnace in a downwarddirection, causing the charge to spread and form outwardly sloping surfaces, supplying electric current to the charge at said sloping surfaces, introducing gaseous nitrogen into the melting chamber, leading off the cyanogen compounds formed, and decomposing the same by means of steam to form am- Inonia.

6. A process for the production of cyanogen compounds of the class herein described consisting in charging the material used downwardly through the shaft of an electric furnace into the enlarged melting chamber of the same to allow the charge to spread and form outwardly sloping surfaces, sup plying electric current to the charge at said sloping surfaces, and introducing gaseous nitrogen into the chamber so that it comes in contact with the charge when heated by the electric current.

7. The herein described process for producing cyanogen compounds which consists in so feeding the charge that it will spread to form outwardly sloping surfaces, electrically heating the charge at the sloping surfaces, and supplying gaseous nitrogen to the charge.

In witness hereof I have hereunto set my hand 1n presence of two witnesses.

AXEL RUDOLF LINDBLAD.

Witnesses AUG HAGELIN, ALMIA DETIEUNAY. 

